earlier, some dimensions were sized as dy + a hardcoded 0.5mm as a way
to adjust for FDM inaccuracy.
with this commit, the adjustment is now moved to a new parameter
box_mfr_tolerance so that it's easier to prepare for different tech
process: FDM, SLA, jet, etc.
the parameter is now set to 0mm because we're moving towards more
accurate processes, SLA and jet. but it is always possible to set this
back to 0.5mm or another value and generate an STL mesh file.
just watch out for freecad's topo naming problem.
this is to align with the naming scheme we came up on the website at
https://nakamochi.io/#editions
essentially, we merged fff, aka DIY, and DIY+ which lived in diyplus
directory, into one called NERD. this is because the simplest DIY didn't
provide acceptable performance characteristics and they are both
suitable for a home-made DIY project anyway. hence, the "nerd" edition
aka "have fun playing around with it on your own".
it also makes things simpler. the other version we'll be making is KAFI.
there are no source files for it yet.
the screws are actually about 2.5mm in diameter, reused from SSD
teardown. they are wide threaded, for plastic.
3mm hole diameter was to accomodate for FDM 3D printers inaccuracies but
it has shown to be too large, especially when produced with SLA or SLS
method.
any time FCStd sources are changed, the generated STL, STEP, DXF and
other derivatives are no longer current. it makes more sense to post and
tag the latter in releases.
this version features a custom heatsink combined with the bottom plate, suitable
for aluminium CNC milling. the construction provides a better heat dissipation
compared to the DIY (FFF) version.
see all details in the readme.
the fuse function in freecad didn't seem to work well when trying to go
back and update individual body parts. this commit is essentially a
remake of the plate + wall parts fuse from 6309e76 as a single body.
the reason to go back and modify individual parts was to move SSD for
more estate, to fit a 90deg connector because a straight cable doesn't
fit.
while there, added missing screws and spacers to the assembly.
this version should be good to start 3d printing.
turned out the cable connector attached to SSD is typically too long to
fit. this 90deg adapter helps.
the SSD is going to be connected to the main board via this adapter
in the next commit.
some first 3d print trials reveal the box might not be sufficiently strong
and easy to print. adding chamfers and fillets helps.
adding chamfers and fillets on plate/wall edges is much easier when the
thing is a single body.
makes it easier to 3d-print in the end.
the plate and walls are still separate parts - easier to work on
separately. it is also possible to even 3d-print them separately, in
which case add a 0.5mm to clearance and plate mount Z in the params
sheet.
this makes it a lot easier to work on a part and look at it in the
assembled view by simply switching tabs. the separate file links to
the original provcase.FCStd. so, need both files to work on the assembly.
it is now possibly to simply select "exploded" or "assembled" option
from a "view" property of the top level assembly std part: no need to
manually modify the asmsheet. the property config is in the same
spreadsheet.
display standoff length now correctly offsets the LCD, the board and top
heatsink while leaving the rest in place. so, it is very easy to change
the overall height.
this change also applies 4.3inch LCD updates from 0c42295 with correct
rpi board mount screw holes, since the LCD master sketch in the
assembly is a copy.
the SSD PCB sits very nicely now. the heatsink model has a pad at the
bottom but it is not the case with the actual sink in use.
will remove it later.
the change also makes the base plate shorter, right about the size of
the display: will be splitting the box in two to allow printing within a max
circle area of 140mm diameter.
this also means the STEP file is replaced with a freecad native file
format.
the master sketch comes in very handy when designing mount and other
constructions around the LCD.
very simple, contains only the essential bits dimensions of which play
important role in the case design due to size restrictions.
there are two std parts: regular with sketches with sketches to
construct the body, and a simple refined version for the provcase
assembly.
the regular variant also has a master sketch to aid in defining
constraints in the provcase design.
all are parameterized via the asmsheet which now includes
a calculation for an exploded view.
while there, added the missing display standoffs.
what's still missing is:
- SSD board
- heatsink top/bottom spacers
- outer case walls and mount holes
alex